Mechanical Enhancement and Environmental Impact of Cement Concrete Pavements Through Lithium Feldspar Powder Incorporation: A Dose‐Dependent Microstructural Study

This study systematically investigated the physicochemical properties and microstructural characteristics of lithium feldspar powder (LFP) using advanced analytical techniques such as X‐ray diffraction (XRD) and scanning electron microscopy (SEM) and conducted a comprehensive experimental program to evaluate the dosage‐dependent effects of LFP on the mechanical properties and environmental compatibility of cement concrete pavement. The main findings indicate: (1) The mesoporous–microporous composite structure of LFP contributes to enhanced interfacial interactions with cement‐based materials. This unique structural feature significantly optimizes the pozzolanic reaction efficiency of concrete, forming a “physical filling‐chemical activation” synergistic effect, which provides a new pathway for improving concrete mechanical properties. (2) Concrete strength exhibits dosage‐dependent behavior, reaching maximum enhancement when incorporating 20% LFP. Although the 28‐day compressive strength of the 30% dosage group (52.6 MPa) was 2.9% lower compared to the control group, both compressive strength and flexural strength still meet structural design requirements. Considering the optimal utilization of lithium extraction solid waste, incorporation of 30% LFP is recommended for practical pavement applications. (3) Environmental impact tests conducted on LFP concrete confirmed that concrete with a 30% LFP dosage complies with regulatory requirements for heavy metal release and ion migration. This study pioneers the introduction of LFP as a primary supplementary material in pavement concrete. It transcends the conventional application boundaries of industrial solid wastes (such as fly ash [FA] and slag) and fills the research gap regarding the high‐value utilization of lithium battery solid waste in road engineering.